Manufacturers of cosmetic products are on an eternal quest to formulate cosmetic compositions that provide better films on keratinous surfaces. The ideal cosmetic film lasts until the consumer wants to remove it by washing with water or using remover compositions. At the same time the film provides a very natural, aesthetic appearance on the keratinous surface without looking fake or “made up”. A suitable cosmetic film should permit the underlying keratinous surface to breathe, retain moisture, and exhibit a superficially attractive appearance that is not too artificial in appearance.
Most often, polymers are incorporated into cosmetic compositions to form the cosmetic film. Generally, such polymers contain many repeating units, or monomers, that give the polymer substantive, film forming properties. Such polymers may be natural or synthetic. Natural polymers such as cellulosics, gums, and resins, have been used as film formers in cosmetics for many years. In more recent years, as polymer chemistry has advanced, polymer manufacturers have been able to manufacture a wide variety of synthetic polymers for use in cosmetics. In general, synthetic polymers fall into one of two classes: silicone polymers (based upon silicon and oxygen), or organic polymers comprised of repeating organic moieties, for example, polymers obtained by polymerizing ethylenically unsaturated monomers such as acrylates or alkylenes, optionally with organic moieties such as amides, urethanes, and the like. Certain synthetic polymers that contain both siloxane monomers and organic moieties are also known.
While synthetic polymers comprised of organic moieties such as ethylenically unsaturated monomers are excellent film formers, they sometimes do not exhibit optimal properties on keratinous surfaces such as skin. Skin is a very dynamic substrate that is in constant movement so cosmetic films that are affixed to skin or lips must exhibit some degree of plasticity. Synthetic organic polymers do not always exhibit the necessary plasticity, and will sometimes crack on dynamic keratinous surfaces such as skin. For this reason, synthetic organic polymers are not as widely used in cosmetic compositions that are applied to skin.
On the other hand, silicone polymers are excellent film formers and have been used to form cosmetic films in many successful commercial products. While silicones provide excellent wear and adhesion in general, organic synthetic polymers often provide desired surface properties that are lacking in silicones. It has been found that a certain silicone polymer, referred to as linear silicone resin, when used in cosmetic compositions, provides excellent substantivity to the composition, promotes formation of a suitable cosmetic film, and provides a light, pleasant feel to the composition.
The term silicone resin has been applied both to and misapplied to a variety of materials over time. Silicone resins as used herein refer to a series of products which include at least two silicone backbones that are joined by a “crosslinking group”. The number of crosslinking groups that are present as a percentage of the total molecular weight will determine the properties of the resulting polymer. Quite to the contrary, our compounds, although the reaction of linear SiH and linear vinyl siloxanes, form elastomeric films when the solvent is removed. We have no crosslinking groups and consequently are quite surprised that the compounds are film formers. While not wanting to be bound by any one theory, we believe that as the polymers grow, “backbiting” occurs forming cyclic structures. A number of materials cyclize forming an interlocked system of cyclic compounds making a film as the solvent evaporates.
Our compounds surprisingly and in an unexpected manner have no crosslinking groups, but form films. As previously stated we believe this is because of interlocking of the cyclic structures. The size of the cyclic is controlled by the choice of raw materials. As will become clear, there are two competing reactions, chain growth and cyclization.
The literature contains many patents that deal with silicone resins. Many patents deal with improvements of the resins. However, there are only a number of classes of resin compounds differing in the nature of the crosslinker. One class is the so called “Q resins”.

The oxygen that needs another bond connects to another polymer as shown:

The crosslinking group is —O—. This type of resin is disclosed in U.S. Pat. No. 6,139,823, incorporated herein by reference. This type of material has a tetrafunctional “Q” group in which the Si has four oxygen atoms attached. This type of resin is very powdery and is rarely used without a plasticizer. This class of compounds can also dry the skin.
The next class of resin contain alkyl connecting groups.

In the case where n=1 a multi functional SiH fluid is hydrosilated with a multifunctional vinyl siloxane. As n is increased the reactant is an alpha omega divinyl compound reacted with a multifunctional SiH fluid.

The SiH polymer is crosslinked with the organic divinyl molecule by reacting the vinyl with the SiH groups using the hydrosilation reaction. The reaction is generally run in solvent such as cyclomethicone (D4 or D5 or hexamethyl disiloxane) or in volatile organic like isododecane. A catalyst, generally a platinum based one, is used to effect the reaction. Chloroplatinic acid or platinum divinyl (commonly referred to as Karstedt) catalyst are preferred. The resulting material is a viscous liquid that when the solvent evaporates provides a film. The commonality here is that until the compounds of the present invention it was felt that all film forming resins had to be crosslinked. Our products refute that long held position.
U.S. patent application 20040180020 entitled Cosmetic compositions published Sep. 16, 2004 to Manelski, Jean Marie; et al., incorporated herein by reference discloses Compositions of the invention containing at least one cyclized dimethicone. The term “cyclized dimethicone” means an organosiloxane comprised of repeating —[Si—O2]—, or “D” units, which form one or more cyclized portions in the final polymer. The cyclized portions, or rings, are formed by cross linking certain portions along the organosiloxane chain to form rings that may be structurally aligned along the polymeric chain. The claimed polymers are known compounds and are stated to have the INCI name dimethicone crosspolymer-3) and isododecane; or JEECHEM HPIB which is a mixture of cyclized dimethicone (dimethicone crosspolymer-3) and hydrogenated polyisobutene and cyclomethicone. Unlike the compounds of the present invention these polymers are cross linked internally with a carbon based cross linking agent. The materials are made by the reaction of an internal silanic hydrogen compound and a divinyl organic. Typical of the reaction is below:

The above compounds are referred to as cyclized dimethicone by the referenced patent application. The cyclization results by the “boxing out” of the silanic hydrogen moiety with the organo functionality introduced with the alpha omega divinyl compound. It will be clearly noted that the compounds so described are not truly dimethicone since there are sections of the molecule that are organofunctional. Also please additionally note the branching pattern is internal, that is the organic functional ring can only occur using non-terminal silanic hydrogen compounds.
The compositions of the present invention contain neither organic cross linkers derived from alpha omega divinyl compounds nor are they internally branched.
In theory silicone fluids with no crosslinking groups can freely rotate and consequently are free flowing oily liquids. If a few crosslinking groups are introduced, the ability to rotate is slightly restricted and the oily material becomes “rubbery”. The rubbery material should be referred to as an elastomer. The properties are morel like a rubber band than plastic. As the percentage of crosslinking increases the molecule becomes more rigid. These class of compounds are resins.
Our compounds surprisingly and in an unexpected manner have no crosslinking groups, but form films. As previously stated we believe this is because of interlocking of the cyclic structures. The size of the cyclic is controlled by the choice of raw materials. As will become clear, there are two competing reactions, chain growth and cyclization. We have surprisingly found that this pattern results in properties heretofore unknown in resin technology. None of the compounds of the prior art anticipate or make obvious the film forming compounds of the present invention.